Medical cannabis reduces severity of symptoms for some patients with cancer, according to new study

April 8, 2019 – BLOOMINGTON, Minn. – A new study of more than 1,000 patients supports early evidence that medical cannabis may help reduce the severity of nausea, pain, insomnia and other side effects associated with cancer and its treatment.

The researchers from the Minnesota Department of Health (MDH) and the Oncology Research Center at HealthPartners/Park Nicollet found that patients with cancer who enrolled in Minnesota’s medical cannabis program reported significant improvement in symptoms, including reduced anxiety, lack of appetite, depression, disturbed sleep, fatigue, nausea, pain and vomiting, within four months of starting the medication.

“It is encouraging to see this evidence that Minnesota’s medical cannabis program is helping cancer patients,” said Minnesota Health Commissioner Jan Malcolm. “In addition to helping people with qualifying conditions, the program was designed to help advance scientific understanding of the treatment potential of cannabis. These latest findings demonstrate that the program is making valuable contributions toward that goal as well.”

The analysis included data from 1,120 patients with cancer who enrolled in the Minnesota medical cannabis program between July 1, 2015, and Dec. 31, 2017. Using a numerical scale, the patients reported severity of eight symptoms prior to each medical cannabis purchase. Many patients achieved a reduction in the severity of symptoms and maintained that benefit for at least four months.

Minnesota’s medical cannabis program is particularly useful to researchers because it relies on manufactured, well-controlled cannabis products and includes a patient registration and survey process.

“Access to medical cannabis products has increased, even though there are only a few large studies that provide good data on its impact,” said Dr. Dylan Zylla, medical director of the Oncology Research Center at HealthPartners/Park Nicollet and co-author of the study. “This study shows us that some patients have a clinically meaningful response to using medical cannabis to control symptoms related to cancer or its treatment and the findings will help direct our future research.”

The research was recently published in the Journal of Oncology Practice. Nearly half of patients who experienced vomiting at the time of their cannabis certification reported the severity of vomiting reduced by more than 30 percent over the four months after their first cannabis purchase. Patients also reported any adverse effects that might be attributed to medical cannabis. Side effects were reported by 11 percent of patients, with tiredness, dry-mouth, and increased appetite being the most common.

“No other state medical cannabis program collects as much information on patients during their participation as Minnesota’s program, and this is a direct reflection of the program's commitment to learning from patient experiences,” said Susan Anderson, MDH research scientist and co-author. “It's gratifying to see the reported benefits and the relatively small degree of adverse side effects experienced by cancer patients.”

More than 30 states have legalized at least some forms of medical cannabis for various diseases. This increase in availability has prompted patients to ask their physicians about using these products. However, data shows that physicians generally feel unprepared to confidently guide their patients in using cannabis products. Zylla and colleagues, including MDH researcher Dr. Tom Arneson, M.D., published survey data in Cannabis and Cannabinoid Research, showing that 65 percent of oncology health care professionals supported the use of medical cannabis, yet 36 percent said they lacked confidence in discussing the risks and benefits of medical cannabis with patients. In addition, 85 percent of respondents wanted more education on the topic.

“The data is promising, but we need thorough, high-quality research like this to continue in order to fully understand both the risks and potential benefits of medical cannabis,” Zylla said. “Our patients with advanced malignancies often focus on quality of life. Finding safe, effective, cost-efficient ways to help them manage symptoms is paramount.”

Independent of MDH, Zylla and colleagues are also in the process of completing a randomized study of patients with advanced cancers to determine how medical cannabis affected pain control and opioid use. Preliminary results are expected in June.